upstream choice modules
diff --git a/src/http/ngx_http.h b/src/http/ngx_http.h
index df97610..96a310f 100644
--- a/src/http/ngx_http.h
+++ b/src/http/ngx_http.h
@@ -32,6 +32,7 @@
 #include <ngx_http_variables.h>
 #include <ngx_http_request.h>
 #include <ngx_http_upstream.h>
+#include <ngx_http_upstream_round_robin.h>
 #include <ngx_http_config.h>
 #include <ngx_http_busy_lock.h>
 #include <ngx_http_core_module.h>